Materials

Purpose

In this lab, you will simulate
how predators locate prey in different environments. You will analyze how color
affects and organism's ability to survive in certain environments.

Industrial Melanism is a term used
to describe the adaptation of a population in response to pollution. One example
of rapid industrial melanism occurred in populations of peppered moths in the
area of Manchester, England from 1845 to 1890. Before the industrial revolution,
the trunks of the trees in the forest around Manchester were light grayish-green
due to the presence of lichens. Most of the peppered moths in the area were
light colored with dark spots. As the industrial revolution progressed, the
treee trunks became covered with soot and turned dark. Over a period of 45 years,
the dark variety of the peppered moth became more common.

Procedure.

1. Place a sheet of white paper on
the table and have one person spread 30 white circles and 30 newspaper circles
over the surface while the other person isn't looking.
2. The "predator" will then use forceps to pick up as many of the
circles as he can in 15 seconds.
3. The number that are left are doubled to represent the next generation
4. This trial will be repeated with white circles on a newspaper background,
newspaper circles on a white background, and newspaper circles on a newspaper
background. Record the data in chart below.

Populations Start on White Background

Starting
Population

Final Populations (how many of the original were left )

Generation

Newspaper

White

Newspaper

White

Double these final numbers to get your starting population for the next generation

1

30

30

2

3

4

5

Populations Start on Newspaper Background

Starting
Population

Final Populations (how many of the original were left )

Generation

Newspaper

White

Newspaper

White

Double these final numbers to get your starting population for the next generation

1

30

30

2

3

4

5

Analysis

1. Describe how the population of moths changed in each generation for both the newspaper and the white moths.

2. What moth coloration is the best
adaptation for a dark (newspaper) background? How do you know?

3. How does the simulation model
natural selection?

4. Examine the table and construct
a graph. Plot the years of the study on the X-axis, and the number of moths
captured on the Y axis. You should have 2 lines on your graph - one for light
moths, and one for dark moths.

Year

#
of Light Moths Captured

#
of Dark Moths Captured

2

537

112

3

484

198

4

392

210

5

246

281

6

225

337

7

193

412

8

147

503

9

84

550

10

56

599

5. Explain in your own words
what the graph shows. What type of environment do you think these moths live in?